:Problem with Looping

Nordlund, Dan (DSHS/RDA) · 2009-11-17T23:37:33Z

> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On > Behalf Of Bruno Giovannetti > Sent: Tuesday, November 17, 2009 3:18 PM > To: r-help at r-project.org > Subject: [R] :Problem with Looping > > Hello, > > Sometimes the looping (using "for") seems to skip some iterations. > > An example: > > arg for (i in seq(.30,.5,.01)) { > arg[i*100-29] } > arg > > What is the problem with this

Nordlund, Dan (DSHS/RDA)

Tue, Nov 17, 2009 3:37 PM

Don't use floating point operations in your indexing.  You may also want to change how you generate your sequence.  This is a floating point representation problem. See FAQ 7.31.  Try something like this

arg <- matrix(NA,length(seq(30,50,1)),1)
for (i in seq(30,50,1)) {arg[i-29] <- i/100 }

Hope this is helpful,

Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA  98504-5204

:Problem with Looping

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